Purification of nitro bodies.



.nitro oswALn' srLBEnRAn, or BUCKHURST HILL, ENGLAND.

PURIFICATION OF NITRO BODIES.

No Drawing. Original application To all whom: it may concern Be it known that I, OsWALo SILBERRAD, a subject of the King of Great Britain and Ireland, and residing at Buckhurst Hill, in

the county of Essex, England, have invented certain new and useful Improvements in and Relating to the Purification of NitroBodies, of which the following is a specification.

This is a divisionof the application filed June 3, 1912 hearing Serial Number 7 01,242. The present invention relates to the purification of nitro bodies and particularly to the purification of nitrated coal tar products of high boiling pointsuch as those described in my application for Letters Patent Serial No. 7 01242 from which this application is a division. Thus it is desirable to submit the nitrated oil obtained as described in my application for Letters Patent Ser. No. 7 012 i2, to further-purificationin so far as that, contrary to all experience with nitro compounds, it will be found thatno amount of washing with soda will raise the heat test of the product beyond three or four minutes, and after a prolonged series of researches the following process was arrived at whereby a stable material which givesla satisfactory heat test is produced. Before passing on to describe this process, I desire to state that I am well aware that it is a common practice to wash-nitroglycerin (i. 6., glycerol nitrate with warm soda, and that certain erivatives of toluene are commonly 1 subjected to the action of alkalis for the production of stilbcne derivatives, but that no such process as that described below has ever been applied to any nitro compound, and that the results of the treatment lead to an entirely novel technical effect, in that by means thereof I am able to produce a stable nonvolatile, liquid nitro hydrocarbon.

The lnventlon consists in purifylng such nit-r0 compounds by stirring-said compounds wit-ha weak solution, say 5 per cent. of soda ash at a temperature of to C. for a period of about twelve to twentyfour hours.

The invention further consists in purifying nitro compounds by treatment with excess of water to which has been added a difficultly .soluble body capable of taking up nitrous acid to form a body inert as regards the nitrated product such as marble or other carbonate or hydroxidsof one or more of the alkaline earths, the liquid being gently Specification of Letters Batent.

Patented May 5, 1914.

filed June 3, 1912, Serial No. 701,242: Divided and this application filed November 23. 1912. Serial No. 733,197.

boiled under a reflux condenser until all the unstable compounds are decomposed.

In the application of my invention, for example, to the purification of nitro derivatives of the high boiling fractions of coal tar, the nitro compound is first stirred witha five per cent. solution of soda ash, preferably 'at about. 50 to 70 C. for a period of about 12 to 2 i hours. The nitro com pound is then separated washed with wa n', and run into a suitable vessel'containing (glean water, preferably about ten times its ulk are added and the whole gently boiled under pounds are decomposed. This process gen: erally occupies from about 2 1 to 48 hours.

Instead of soda ash the carbonates, bicar' bonates or hydroxids of any of the alkali metals or mixtures containing any or all of these may be used. Similarly, instead of marble, I may use chalk, dolomite, magnesia, or the carbonates or hydroxids of any or all of the alkaline earths or mixtures of and a few lumps of marble or the like,

I a reflux condenser until all unstable comthese or any compound difficultly soluble and capable of taking up the nitrous acid produced by the gradual decomposition of the unstable products.

When nitro derivatives of the higher boiling-point fractions of coal tar referred to in my application for Letters Patent Serial No. 701242 are purified by the process above described, I find that the productis not only rendered stable, but undergoes other changes. Thus, the viscosity is altered. and the tendency to solidify is lessened, while the quantity of solid produced in the event of solidification occurring is reduced. H'her insufliciently ure or mixed lllll'O compounds may be purl ed in a similar manner. The treatment s, therefore, of

are required for the manufacture of explosives, and especially of plastic explosives,

as by means of the purification great stability, which is essential in such explosives, can be obtained.

By purification by means of carbonates or.hydroi :ids of the alkaline earths either with or Without previous treatment with soda ash or the like I find that the heat test of the product is greatly raised, whereas purified in the ordinary manner, nitrated burning naphtha, solvent naphtha, and prodconsiderable importance when the products ucis produced according to the process described in my said application for Letters Patent; seldom show a heat test exceeding five minutes. Further, the tendency of the n.'odnctto freeze and the consequent difficulty and danger of thawing is reduced.

liming now described. my invention What I claim as new and desire to secure by Letters Patent is 2 A process for purifying nitro compounds. of the aromatic series which consists in mixing such compounds with a Weak solution of soda. ash in the warm, and then treating the mixture with an excess of water OSWALD SILBERRAD.

dtncsses;

J. W. Pivl'cinxo, E. C. Ti-ioiu'.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, D. G. 

